SNLA299 August   2018 LMH0324 , LMH0397 , LMH1208 , LMH1218 , LMH1219 , LMH1297

 

  1.   LMH12xx MADI Compatibility Application Note
    1.     Trademarks
    2. 1 MADI Specification Requirements
      1. 1.1 MADI Transmitter Electrical Requirements
        1. 1.1.1 Line Driver Impedance
        2. 1.1.2 Mean Output Voltage
        3. 1.1.3 Maximum Output Voltage
        4. 1.1.4 Terminated Signal Rise and Fall Time
      2. 1.2 MADI Receiver Electrical Requirements
    3. 2 LMH12xx Device Family
      1. 2.1 LMH12xx Device Family
        1. 2.1.1 LMH1297 MADI Modes of Operation
          1. 2.1.1.1 Dual MADI Cable Driver
          2. 2.1.1.2 SDI Bidirectional IO and MADI Cable Driver
          3. 2.1.1.3 Bidirectional MADI Port and SDI MADI Cable Driver
          4. 2.1.1.4 Bidrectional MADI Port and SDI Cable Driver
        2. 2.1.2 LMH1297 Device Family Register Changes for MADI Compatibility
        3. 2.1.3 LMH1297 Device Family Hardware Changes for MADI Compatibility
      2. 2.2 LMH1218 Device Family Hardware Changes to Support MADI Compatibility
      3. 2.3 LMH1219 Device Family Recommended Register Settings
    4. 3 Summary
    5. 4 References

2.1 LMH12xx Device Family

The LMH1297 and LMH0397 device families are 75-Ω bidirectional IOs, which means the devices can be configured either as adaptive cable equalizers or as dual cable drivers. When the user configures one of the devices as an adaptive cable equalizer, there is an additional loop-through port that can be used as an SDI or MADI cable driver, if needed. The LMH1297 device family can be controlled either through a register or pin. Through register control, the cable driver output amplitude can be controlled in 5-mV resolution or per step. Figure 4 shows these configurations.

fbd1-snla299.gifFigure 4. LMH1297/LMH0397 Block Diagram